Particles follow words in a sentence. Each particle is used to indicate different things. Here are some particles:

は this is the topic particle it is used to so the topic of the sentence. While it does us the character that is read "ha" when it is used as a particle, it get read "wa" instead. When the topic of the sentence is implied to already be know, it isn't uncommon to see the topic, and its particle to be excluded. Here is an example: あなたのせんこうはなんですか。にほんごです。 which translates to "What is your major? It is Japanese." In the first sentence, the topic is stated, but in the second it isn't needed because both the speaker and the listener know what the topic is.せんこう -- majorにほんご -- Japanese language

を is the object particle and is read "o". It is used mark the direct object. This object is either being affected by, or involved with the verb of the sentence. Here is an example: わたしはひるごはんをたべます。 which translate to "I will eat lunch." In this case, the particle を is being used to show what the topic, わたし, will be preforming the action, たべる, on the object, ひるごはん.ひるごはん -- lunch

で has multiple uses, but for now I will only be going over one use for this particle. で can be used to show the location in which the action is happening. Here is an example: わたしはうちでみずをのみません。 which translates to "I won't drink water at my house." The で is being used to say that the action, のむ, takes place at the location that is followed by で, うち.うち -- house or home

に also has multiple uses as a particle, but I will go over two of these uses.1) に is used to mark the goal of movement. An example of this is: あなたはきょうとにいきますか。 which translates to "Will you go to Kyoto?" When に is used in this sentence, it is being used to say that the topic, あなた, is going, いく, to the location that is followed by に, きょうと. When に is used this way, it is normally with a verb that indicates movement, like いく.きょうと -- "Kyoto" a city in Japan2) に is also used to mark times that are not dependent on "now" like "tomorrow" is. An example of this is: じゅういちにねます。 which translate to "I will go to bed at eleven." In this case the topic is implied and as such isn't mentioned. The specific time, じゅういち, is then followed by the particle に, this is used to say that the verb occurs at that time. If the time is relative to "now" then the particle is not needed. An example of this is: あしたのあさねません。 which translates to "I wont sleep tomorrow morning." In this case the particle に is unneeded.あした -- tomorrowあさ -- morningIt is possible to use に for both of these uses in one sentences. Here is an example: わたしはがこうににちようびにいきません。 This translates to "I won't go to school on Sunday."がこう -- schoolにちようび -- Sunday

へ is another particle that is used to so the goal of movement. When being used as a particle, it is just read "e" not "he." Even though へ can be used to show the goal of movement like に it cannot do the other things that に does. Here is an example of using へ with the same sentence I used for に: あなたはきょうとへいきますか。 which also translate the same way to "Will you go to Kyoto?" Both に and へ can be used interchangeably in this case, but there are slight differences, that I will go over later.

Sentences in Japanese normally follow this order: topic, time, place, object, verb, but many of these part can be moved around.